# :::::::: ? Colon-Dot-Question Mark Puzzle

I'm hoping you can find an answer to a puzzle that is troubling us greatly at another forum. If any of you can find an answer, that will help greatly; the creator of the puzzle had to go to the hospital for several days, so he won't be able to tell us the answer for a long while, and we're completely stumped.

Here's the whole puzzle:

:::::::: ?

Yup--that's it. Eight colons and a question mark. Make sense of that if you will.

Just so you know, I don't have any answers for you; we're completely stumped. Has anyone seen this one before, or does anyone know an answer?

Many thanks.

EDIT: Let me add a few solutions we've discarded/we've discussed with the creator of the puzzle ("Pete" at that link) before he left for the hospital. I looked up several different meanings of colon, and Pete let me know that "No, sorry. I can confirm it isn't the word 'colon,'" which tells me that it's not something like colonate or colonnade or something like that, which I suggested, but rather that it's the ":" symbol itself.

SECOND EDIT: Someone at that forum--Tarathian123--sent it to a friend of his who's a mathematician and computer programmer. He was also unable to figure it out.

• Looks like some kind of rebus? – Rand al'Thor Jun 17 '17 at 15:13
• Have you tried decoding it using braille? That might work. – Clangorous Chimera Jun 17 '17 at 15:49
• Perhaps it's not just the same letter all through. Maybe? I'll post a partial solution to show what I mean. – Clangorous Chimera Jun 17 '17 at 15:57
• Morse code? Eight dots over / below eight dots. Means : She over she? – Jamal Senjaya Jun 17 '17 at 16:31

nothing; "::"

explanation:

I think @Sneftel is on the right track, except that it is not a true-false question of the form

p : q :: r : s ?

i.e. is p to q as r is to s?

but a standard analogy question of the form

p : q :: r : ?

i.e. p is to q as r is to what?

It only remains to define p, q, and r as strings of colons such that the total number of colons assigned is four. Most of the possible assignments do not yield very interesting questions.

Setting p = ":", q = ":", and r = "::" gives the tautological

":" : ":" :: "::" : ?

which should be read "is to is to is to as as is to what"

Similarly, p = ":", q = "::", and r = ":"gives the tautological

":" : "::" :: ":" : ?

which should be read "is to is to as as is to is to what"

Both have the answer "::" but for different reasons.

Setting p = "::", q = ":", and r = ":" gives

"::" : ":" :: ":" : ?

which should be read "as is to is to as is to is to what"

which seems to indicate the answer "" i.e. nothing.

Now, with nine colons and a query you can make some interesting questions.

• Many thanks, A.I. Breveleri, but I'm still not sure about this kind of solution. If the analogy is tautological, how does it count as an analogy? And what is the possible meaning? – Salzmank Jun 17 '17 at 21:20
• A.I. Breveleri, Pete got back to us, and you were correct, except that the solution is one dot--"." Thus: four dots is to two dots as two dots is to dot. Now, that is an analogy. Many thanks for your answer, and excellent work! – Salzmank Jun 17 '17 at 22:46

The line is an analogy, expressed in the form seen on standardized tests, but with the spaces removed. With the structure highlighted, it reads as follows: ::::::::? That is, "do two dots bear the same relationship to two dots, as two dots bear to two dots"? The answer is trivial.